Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS

Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC

Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

Y10T137/00—Fluid handling

Y10T137/2496—Self-proportioning or correlating systems

Y10T137/2559—Self-controlled branched flow systems

Y10T137/2574—Bypass or relief controlled by main line fluid condition

Y10T137/2577—Liquid level responsive

Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS

This invention relates to a new and improved liquid dispensing system and more particularly to such a system especially adapted for fueling vdryy hose for fuel delivery. Such a dry hose system is important where comparatively large hoses are used to allow rapid supply of fuel. In airplane fueling, hoses are of substantial length and a large hose filled with gasoline isl heavy and difcult to handle. A difficulty presented with the use of large and long hoses under the dry hose system is the fact that such a hose becomes dangerous when suddenly filled with gasoline under substantial pressures. Such a hose may also have a capacity of a large quantity of gasoline and it is important to provide accurate metering of the gasoline actually delivered to the plane. It is therefore important that the yapparatus be designed to meter the actualdelivery from the nozzle and not the gas used to fill the dry hose.

It is an object of the present invention to provide a new and improved liquid dispensing apparatus of the dry hose type.

It is a further object to provide such a system adapted to ll the dry hose at a lower pressure and dispense liquid at a higher pressure.

It is also an object to provide a system of this character in which the lower pressure hose ll and higher pressure dispensing operations are normally automatically controlled and in which such operations may be manually controlled if desired.

It is an additional object to provide a system having a meter and counter which are not operated during the hose lling operation, but are operated during the higher pressure dispensing operatiom, K

It is another object to provide that such meter operation is automatically controlled.

'It is a further object to provide such a meter and counter associated with the dispensing ap-- paratus in such manner that the meter is normally not operated when draining the hose, but which may be-operated if desiredwhen defuel# ing a plane or the like.

It is also an object to provide a system including electronic controls which may be in part manually operated and in part operated by fluid pressure.

It is an additional object to provide a. system in which such electronic control may be in part operated by fluid pressure at or adjacent the discharge nozzle of the hose.

It is a further object to provide dispensing apparatus of this type in which variation of pressures to the delivery hose is accomplished independently of the pressure pump.

It is also an object to provide a construction in which a portion of the fluid flow from the pump may be lay-passed back to the source'of vsupply in order to modify flow and pressure in the hose.

It is an additional object to provide a control system which, in the event of control failure, will automatically restore the apparatus to safe condition with an empty hose.

It is another object to provide liquid dispensing apparatus designed for commercial produc-` tion and use.

Other and further objects will appear as-the description proceeds.

Certain preferred embodiments of our inven' tion have been shown in the accompanying drawings in which- Figure 1 is a somewhat diagrammatic showing,

partly in section, of the apparatus. the parts an enlarged scale, of the solenoids and slide valves with the parts in position for slow ll; Figure 5 is a diagrammatic showing of the electronic control circuit;

Figure 6 is an elevation of the hose nozzle and l Figure l0 is an enlarged view, partly in sec-` tion, of the pressure switch.

3 `Referring first to Figures l, 2 and 3, the apparatus includes a high lift rotary pump 22 which may be of any suitable construction, The details of this pump form no part of the present invention and will not be shown or described in detail. The suction inlet passage 24 is connected to the iiange 25 at the inlet side of pump 22. This inlet passage 24 communicates through an opening normally closed by the inlet valve 21 carried on stem 28, with an entrance passage 28 in com-l munication with a pipe 38. This pipe 30 leads to any suitable tank or other container for the gasoline or other liquid to be dispensed.

The inlet passage 24 communicates with the by-pass passage 32 which leads through check valve 34 and pipe 85 to the valve chamber 31. Evacuation valve 88 is adapted to be seated to close the valve passage 48 leading from valve chamber 31 to the common chamber 4|. The discharge valve 43 normally closes a valve opening 45 between the common chamber 4| and the discharge passage 41 leading from the pump 22. A passage 48 connects the pump discharge passage 41 to pipe 5| which leads to chamber 53 above the return valve 54. This return valve 54 is carried on stem 55 guided in spider 58 which stem is aligned with stem 28 oi' the inlet valve 21. The return passage 58 connects the port controlled by valve 54 to passage 51 which leads to the entrance chamber 28.

A perforated control line 58 extends across the discharge passage 41 and is connected by passage 8| to a cross passage 83 in the slide valve housing 84 above which is located the solenoid housing 85. A control passage 88 leads from the valve chamber 31 to a control chamber 88 1ocated in the lower part of the slide valve housing 84. This control passage 88 is provided at its upper end with a ball check valve 1| which permits passage of fluid only from the control chamber 88 to the control passage 88.

The dispensing passage 13 leads from common chamber 4| to the meter 15. 'I'his meter is connected to a counter or indicator 11 by means of a. clutch, not shown, so that the counter may be put in and out of operation as desired. The outlet 18 of meter 15 is connected through hose 8| to the switch housing 83 and dispensing nozzle 38. The grounding portion 88 of the control wire |83 is connected to nozzle 85 and provided with plug 81 for connection to the plane being serviced.

The inlet valve 21 is carried by stem 28 andl that chamber. That portion of stem 28 extend-` ing above chamber 88 is adapted in the upper position of the piston 88 to engage the underface of valve 54 and hold that valve closed. That portion of chamber 88 abovethe piston 88 is connected by passage 8| to passage 88 which leads into the slide valve housing 84 adjacent the right hand slide valve 85. The lower portion of chamber 88 below the piston 88 is connected by passage 81 to an upper passage 88 also extending into the slide valve housing 84 adjacent the slide valve 85.

The passage 83 leading from slide valve housing 84 in addition to being connected to passage 8| is connected to passage |8|, which passage leads into the upper portion of chamber |03 above the piston |85. This piston is carried upon, the upper end of the stem |81 which carries the discharge valve 43. 'I'he lower portion of chamber |83 below piston |85 is connected 4 by passage |88 with passage 88 leading into the slide valve housing 84. It will be noted that a spring is placed about valve stem |81, this spring engaging 4the upper face of discharge valve 43 and normally holding that valve in closed position upon its seat.

The evacuation valve 38 is carried on stem H3 which extends into chamber ||5 where the stem carries the piston ||1. The lower part of chambei ||5 below piston ||1 is connected by passage ||8 with the slide valve housing 84 and communicates with the left hand slide valve 212i. Similarly, the upper portion of chamber lili above piston ||1 is connected by passage |23 with the upper portion of slide valve |2|. The chambers |25 and |28 are located above the slide valves and i2|, respectively, and these chambers are connected by passages |28 and |28, respectively, with the cross passage 83 in the slide valve assembly block 84. The slide valves 85 and |2| are urged upwardly by the springs |3| and |33 located below the slide valves. 'I'he passage |35 leads from the chamber |28 to valve |38 and the similar passage |38 leads from chamber |25 to the valve |38. The valves |38 and |38 are both connected to the pipe |4| which connects down to the by-pss Passage 32.

'I'he solenoids |45 and |41 are carried in hausing 85 and are adapted to operateplungers |48 and |50, respectively. These plungers normally rest on the associated slide valves 85 and |2|, which valves are normally held in the lower position against the action of springs |3| and |38 by the nuid pressure in the system. The solenoids |45 and |41 are connected by wires |53 and |54, respectively, to the electronic control panel within the housing |51 and both are connected to this control panel by the common wire |55. The electronic control panel within housing |51 is also connected by wires |58 and |88 to a clutch operating solenoid carried in housing |8| on the counter assembly 11. The electronic control panel in housing |51 is further connected by wire |83 which leads to a switch mounted in housing 384 mounted on the counter or indicator housing 11, leading through hose 8| to the hose switch assembly in housing 83.

In Figure 4, the solenoid and slide valve construction is shown on an enlarged scale, the view being from the reverse side to the somewhat diagrammatic showing of Figures 1, 2 and 3. The slide valve housing 84 is provided with a pair of vertically extending cylindrical openings 20| and 203 and in these openings are located the ported sleeves 205 and 281. The slide valves 85 and |2| move freely in the sleeves 205 and 281. 'I'he solenoids |45 and |41 are in the housing 85 and are fitted about the tubular members 208 and 2| 8 which, as shown, have closed upper ends. The plungers |48 and |58 move freely in the axial openingsin the sleeves 288 and 2I0. The two plungers 48 and 58 are similar and, as shown in connection with plunger |58, are provided with internal bores 2|2. They are also provided with reduced lower sections 2|4 and 2|5 in which fit the movable valve members 2| 1 and 2|8. These latter members are provided with elongated slots 228 and 22| iltted about cross pins 223 and 224 which pins are fixedly secured in the reduced lower portions 2|4 and 2| 5 of the plungers |48 and |50. The valve members 2|? and 2|8 are thus permitted a limited movement relative to the plungers |48 and |58. The slide valves 85 and |2| are provided with internal bores 228 and 221 with reduced upper portions 228 and 230 which are adapted to be closed lby the valve members 2|1 and 2 I8 when those members are in their lower position.

When the solenoids |45 and |41 are not energized the plungers |48 and |50 are in their lower position, sealing ports 229 and 230. Closing these ports puts chambers and |26 under pressure when the pump is operated and this pressure forces the slide valves into their lower position compressing springs |3| and |33 as shown in connection with spring |33 and slide valve |2| at the right of Figure 4. In this position the shoulder 232of the sleeve valve |2| rests on the upper portion 234 of the ported xed sleeve 201.

The solenoid |45 at the left of Figure 4 is shown as energized. Itv has drawn the plunger |48 to its uppermost position and the valve member 2 1 has been carried up by the pin 223. The port 229 in the sleeve valve 95 is thus opened, equalizing the pressure on both sides of the slide valve 95 and as aided by spring |3| raises it to its uppermost position.

The cross section shown in Figure 4 does not include all of the passages communicating with the ported sleeves 205 and 201, as these passages enter in different planes. However, the relative positions and functioning of these passages are fully shown diagrammatically in Figures 1 to 3, inclusive.

The valve and nozzle assembly is shown in Figures 'I to 10, inclusive, together with the control switch arrangement. The hose 8| carries the switch housing 83, the switches being contained in an upwardly projecting-chamber 240, shown in longitudinal section in Figure '7 and in cross section in Figure 9. The nozzle 85 is shown in Figure 6 as connected directly to the switch housing 83, the nozzle containing the usual type of manual control valve (not shown) actuated by plunger 242 and hand lever` 244. The grounding portion 86 of the control wire |63 is shown as connected with the nozzle structure and is provided at its free end with the plug 81 for connection to the plane being serviced.

The switch chamber 240 contains a U-shaped frame 246 at which are secured a pair of switches 248 and '249, switch 248 being of the normally open type and 249 being connected normally closed. These switches are operated by depressing plungers 25| and 253, respectively, and are operated only so long as these plungers are held.

down. The switch 248 is the Off switch and such a designation may be imprinted on the top housing member 254 adjacent the diaphragm 255 located above that switch. The switch 249 is the On switch and may be so designated on the cover member 254 adjacent diaphragm 251 above that switch. A resilient member 259 formed of spring metal has a central portion secured to the underface of the cover member 254 of chamber 240 by means of the screws 262 and plate 263. The member 259 has one portion 264 carrying button 265 extending under diaphragm 255 with its free end located above the switch :button 25|. Consequently, downward pressure on the resilient diaphragm 255 depresses button 265 and moves the portion 264 of member 259 downwardly to engage and depress switch button 25| to operate the Oi switch. The On" switch 249 is operated in a similar manner by depressing diaphragm 251 against button 261 secured to the left side 269 of member 259.

The pressure control switch 210 is enclosed in housing 21| screwed into the bottom of chamber 6 240, the housing being open to the pressure in the switch housing 83 through the port 213. The pressure switch is shown in detail in Figure 10, the housing 21| enclosing a diaphragm 215 which diaphragm has its edges secured permanently in place as at 216 by a pressure tight seal. The underface of diaphragm 215 is exposed to pressure in the hose line through the bore 213. The upper face of diaphragm 218 carries an insulating disk 280, the diaphragm being normally held in the A position shown in Figure 10, by means o! compression spring 282 which bears against the upper face of this insulating disk 280. The insulating disk 280 carries a metallic contact member shown at 283, this member being arcuate in form and extending under the contacts connected'to terminals 285 and 286. Consequently, when the pressure in the hose builds up to a predetermined amount it forces the diaphragm 215 upwardly to close the circuit between these contacts and connects terminals 285 and 286 by means of the member 283.

The insulated fluid tight, through connection 288 extends between the interior of chamber 240 and the interior of housing 83 to connect the control line |63 to the switch assembly in the housing. c

The switch wiring is shown diagrammatically at the lower left of Figur'i, and shown in plan in Figure 8. The control 'wire-|63' isconnected to Off switch 248. The Opposite side ofswitch v248 is connected by wire 289 to iterminal`286 of pressure switch 210. Thesame-jterminal 286 of pressure switch 210 is connected"by resistor 353 to the On switch 249. 'The other-'terminal 285 of pressure switch 210 islgrounledby wire 290. The other side of the"0n"'switch 249 is connected to ground by wire 29|.'` f i- .i-

The electronic control enclosed in control housing |51 shown in Figures-1 ,l2and 3 is shown diagrammatically, together with associated control lines and switches, in Figure 5. WVThis control is for the operation of the lsolenoids |45 and |41 shown in Figures 1, 2,'3 and 4 within housing 65 and for energizing the meter registerV engaging mechanism solenoid which Yis'fin Vhousing |6| in Figures 1, 2 and 3. The control' system in housing |51 of Figures 1, 2 and''3;as`show`r`iI in Figure includes relays 30| and 303, a transformer 305, a vacuum tube 306, resistors 308 and 309, capacitor 3|| and variable resistance 3|3. The transformer primary 3|5 is connectedl to a source of electrical energy (which is here assumed to be alternating current, although direct current could be utilized with only slight modifications) through fuses 3|1 and 3|8 and through lines 3|9 and 320. Application of this electrical energy results in the heating of the filament 322 of the tube 306 to bring. said tube to operating condition, since a closed circuit exists from one end of the transformer secondary winding 324 through line 325, filament 322, and ground connection 321 to the other end of the transformer secondary winding 324.

During the positive one-half cycle of the voltage in the secondary winding 329, current ows through line 33|, resistor 309, line 333, cathode 335 and plate 336 of the lower half of the tube 306, and line 338. This half of the double triode tube 306 has its grid 840 connected to the plate and is operated as a diode half wave rectier. During the negative one-half cycle on current ilows. Thus a direct current flows through line 33|, resistor 309, line 333, the lower half of the tube 306, and line 338. The plate 336 and the grid 340 are at a positive potential with respect to cathode 335. The cathode 335 is connected to ground. The previously mentioned direct current voltage is applied across resistor 300 and variable resistance 3|3 causing a direct current to flow from point 342 through variable resistance 3|3, resistor 300, and the upper half of the tube 300 from grid to cathode 322. The above said current causes a voltage drop across resistor 300, which applies a negative bias on grid 344. Variable resistance 3|3 regulates the current flow through resistor 308, which in turn regulates the voltage drop across resistor 308, thus regulating the negative bias applied to grid 344.

During the positive one-half cycle of the voltage in the s ceondary winding 345, current will ow through line 341, through the operating coil of relay 30|, the operating coil of relay 303, line 333, the upper part of tube 305, and line 35|, provided the negative bias applied to grid 344 is positive enough with respectto the cathode 335 to allow current to flow through the tube between cathode 335 and plate 348. During the negative one-half cycle, no current ilows except the discharge current oi.' the capacitor 3| I, which has a discharge period longer than one-half cycle. This discharge current insures a continuous flow of current, keeping the relays 30| and 303 from chattering.

The variable resistance 3|3 is adjusted so that the negative bias on grid 344 will prevent the -upper portion of the tube 300 from conducting when the OfP control switch 248 is moved to its Oil position and also so that the control will operate with the ground return circuit resistance 353 within the limits of predetermined values. when the On control switch 245 is moved to its On" position or the pressure switch 210 shorts out both the resistor 353 and the On switch 243.

Pressing the On" switch button 240 places the control wire |03, resistor 353, and ground return path through wire 80 in parallel with resistor 303 and the tube 305 path from grid 344 to cathode 335, thus reducing the current flow through resistor 308, which lowers the negative bias on grid 344 causing a predetermined amount of current to ilow through line 35|, transformer secondary winding 348, line 341, operating coil of relay 30| and operating coil of relay 303, and line 333. This amount of current, being insumcient to close relay 303, is of a suilicient amount to close relay 30|, the relay 30| being more sensitive than relay 303. Actuating relay 30| closes contacts 302 and causes current to flow through the line 351 from line 3|8 and from line 351 to line |53 and to the slide valve solenoid coil `|45 and through lines |55 and 350 back to-line 320. resulting in slow ll. Thus the hose starts to fill.

When the hose has illled with fluid, the pressure switch 210 in the nozzle switch housing 03 shorts out resistor 353. thus decreasing current ilow through resistor 308, which decreases the negative bias on grid 344, causing a larger amount of current to ilow through line 35|, secondary winding 340, line 341, the operating coil of relay 30| and also the operating coil of relay 303, and line 333. This amount of current is sumcient to actuate the relay 303. closing its contacts 304, which causes current to ilow through line 351. contacts 302 of relay 30|, to actuate solenoid |45 and also contacts 304 of relay 303, line |54 to solenoid coil |41, and line |55 toline 350. thus allowing the full discharge of the pump to enter the hose. The closing of the contacts 304 of relay 303 also causes current to flow through line |50 to the meter register engagin'sr mechanism solenoid coil 30|, in housing |5| and line |55 to line 350. This enables the meter to register the iluid passing through it when the nozzle on the end of the hose is opened and liquid is being discharged.

Pressing the "OiT switch button 248 opens the control wire circuit which. returns the current through the resistor 308 to the original value which causes the negative bias on grid 344 of the upper section of tube 308 to go beyond cutof! value, which stops current flow in the upper section of tube 305 from cathode 335 to plate 322, through line 35|, transformer secondary winding 345, line 341, operating coil-of relay 30| and operating coil of relay 303, and line 333, causing contacts 302 of relay 30| to open, .which interrupts current flow through the valve solenoid coils |45 and |41 and meter solenoid 35|, causing the valves to be returned to their normal positions so as to evacuate uid from the hose and to disengage the meter register engaging determined and preset amount of liquid haspassed through the meter. The mechanism for actuating switch 384 forms no part of the present invention and has not been shown. It will be apparent however that opening switch 384, which is normally closed, will have the same effect on the control system as pressing and opening the stop switch 240.

It will be noted that this electronic control has been so designed that the electric energy carried by the control wire in the hose is of such a low level that, when the control wire circuit is broken by any switch or other means, no spark is formed that will ignite gas in a hazardous atmosphere.

The three positions of the valves and control devices are shown in Figures 1, 2 and 3 of the drawings. Figure 1 shows the valves in such a position as to create suction on the hose and evacuate the hose. It will be understood, of course, that the parts are also in this position when the system is used to withdraw gasoline from the tanks on an airplane or from other similar tanks and return the gasoline to the main supply tank.

' As shown in Figure 1, the inlet valve 21 is closed and therefore the suction end of the pump 22 is not connected to the main supply tank through pipe 30. The suction intake inlet passage 24 of the pump is, however, connected through pipe passage 32 and through check valve 34 and pipe 35 to valve chamber 31 This valve chamber is open to the common chamber 4| since evacuation valve 30 is raised. The common chamber is connected through dispensing passage 13 to meter 15 and to the hose 8|. The discharge valve 43 is closed so that the discharge of the pump through discharge passage 41 cannot enter the common chamber 4|. This pump discharge goes through passage 43 to p'ipe 5| and to chamber 53 above the return valve 54 which is opened by 9.. the pressure. The liquid passages 56 and 51 tothe entrance chamber 29 and back through pipe 30 to the main supply miaround slide valve 95 and through pipe 93 to pipe and to the upper portion of chamber |03 above piston |'to hold the discharge valve 43 closed. Pressure from cross passage 63 also goes around the other slide valve |2| to pipe H9 and into the lowervportion of chamber ||5 below the piston ||1 to open the evacuation v alve 39. `Further, pressure passes from the right hand slide passes then through valve 95 through pipes 93 and 9| to the upper v portion of chamber 88 above piston 89 so as to force that piston downwardly closing the` inlet valve 21. v

It will be noted that under this condition both of the slide valves 95 and |2| are held down by the uid pressure in the system as neither solenoid |45 or |41 is actuated. Therefore, this is the position which the parts take in the case of control failure when no current is supplied to the control apparatus. This is the safe condition withthe hose evacuated and no gasoline being discharged by the equipment.

It is to be noted that under the valve conditions, as shown in Figure 1 and as described above, the opposite sides of the control pistons |05, ||1 and 89 are all exposed to suction. Suction passes from suction chamber 31 through passage 66 to the suction chamber 68 in the lower part of the slide valve assembly 64. Suction passes up through the central ports 226 and 221 in the slide valves 95 and |2| and from slide valve 95 through passage 99 and passage |09 to the underside -of the piston |05 in chamber |03. It also passes from passage 99 through passage 91 to the underside of piston 89 in chamber 88. In addition, suction passes from slide valve |2| through passage |23 to chamber ||5 above piston ||1.

As shown in Figurel 2, the parts are in position for slow illl. By slow fill is meant a condition under which fluid under pressure is .supplied l,through dispensing passage 13 to meter 15 and hose 8|,y but a portion of the fluid under pressure is also bypassed to the intake side of the pump. Therefore, because of this by-pass, the supply to the hose is at a substantially lower pressure than if all of the discharge from the pump went directly to the hose. The difference in the adjustment of the several valves from that in which they are shown in Figure 1, is caused by the lifting of the slide valve 95, the slide valve |2| remaining in its lower position. The solenoid |45 is actuated by the electronic control means. shown in Figure 5 and previously described, and lifts the plunger |48 from slide valve 95. The slide valve 95 moves upwardly due to the force of the spring |3I. It now serves to connect the cross passage 63 to the opposite passage 99 and the passage 93 previously connected to pressure is now directly opened to the suction chamber 68 in the lower portion or the housing s4. Under these` conditions pressure is supplied through passages 6| andy 63 to passage 99 from which pressure is supplied through passage |09 to the underside of pistonr |05 in chamber |03, thus lifting the discharge valve 43. Pressure is also supplied from passage 93 through passage 81 to the underside of piston 89 in chamber 88 lifting the inlet valve 21.

- The movement of piston 89 also closes valve 54.

remains in its lower position since solenoid |41 is not operative.

With lthe valves, as shown in the positionsof Figure 2, the fluid delivered under pressure from the pump 22 goes through discharge passage 41'- to the common chamber 4| where a portion of it goes through dispensing passage 13 to the meter 15 and hose 8|. Since the valve 39 is open, a

4portion of the 'fiuidunder pressure also leaves common chamber 4| through valve opening 40 and passes from chamber 31 through pipe 35 pastv check valve 34 and through pipe 32 to the suctionr inlet passage 24 and is recirculated through the pump.` Fluid under pressure will also flll passage 49, pipe 5| and enter chamber 53 above valve 54, but its movement is blocked at this point by valve 54 which is closed.

In the position of the valve shown in Figure 3, the solenoid |41 is operated and the plunger |50 lifted from slide valve 2i so that that slide valve is raised to its upper position by spring |33. The other slide valve remains in its upper position in which it is shown in Figure 2. The upper movement of slide valve |2| serves to reverse the flow of pressure and suction to chamber ||5 so that there is pressure in the upper portion of this chamber above piston ||1 and suction below the piston |1 and the valve 39 is closed. Under these conditions of valve position the fluid under pressure from pump 22 enters the common chamber 4| through the discharge passage 41 and is blocked from movement in any direction ,except through the dispensing passage 13 leading to the meter 15 and hose 8|. Therefore, the fluid under pressure is supplied at full pressure to the discharge hose.

It will be understood from the previous de-v scription of the control system shown in Figure 5 that the shift from the evacuation position of Figure l to the vslow fill position of Figure 2 is accomplished by pressure on the On button 249 which serves to actuate solenoid |45. The shift from the slow fill position to the fueling position is automatic and takes place as soon as the hose is full. This is caused by the fuel pressure in the switchv housing 83 which actuates the pressure switch 210 which changes the circuit so that solenoid |41 is also actuated.

\During the slow fill operation and also during the evacuation operation the solenoid 36| in housing |6| of Figures l, 2 and 3 is not actuated and the counter or indicator 11 is not connected to the liquid measuring portion of tne'meter 15. When the solenoid |41 is actuated to bring the system to the fueling position the solenoid 36| is actuated and the counter 11 is clutched to meter 15 and all liquid delivered from the hose is measured and the amount is recorded and indicated. When the hose is evacuated, with the parts as shown in Figure 1, it is not desired to measure theV liquid withdrawn from the hose as it was not measured when it was introduced into the hose.

When withdrawing fuel from the tank of a plane or from any other tank through the hose, it may be desired to measure the liquid withdrawn.

For this purpose a manual clutch lever 295 isk provided by means of whichthe counter clutch may be operated independently of the solenoid 36| inhousing |6I. `1

It will be apparent that the system will always The position of this valve 39 is conf revert to the evacuation or safe position in the event of control failure. 'Ihis will happen if control current is interrupted or it the grounding portion 23 of the control wire |53 either purposely or accidentally loses its ground connection to the plane being fueled. This will also happen when the switch 3M is opened by a limiting action when the amount preset on the meter has been delivered. It also happens when the Stop button on the switch housing I3 is. pressed. Il the system fails, it fails in the safe position.A

The manual operating valves |33 and |32 can be used to change the valve positions manually, it the` automatic control, by means o! the solenoids and slide valves fails. It will be apparent that under all conditions shown in Figures l, 2 and 3, there is pressure on the right side of these valves through pipes |35 and |33. Under all conditions also there is suction on the lett side of both valves |36 and |39 through pipe lll which leads through by-pass passage 32 to the pump inlet passage 24. Consequently, if valve |39 is opened it will transmit suction from the pump intake through line |33 and through the chamber |25 above slide valve 35 through the interior passage 228 in the slide valve to the lower chamber 58. Similarly, pipe |35 is connected to the chamber |26 above slide valve |2|, this chamber being in communication with the axial passage 221 through the valve.

With the slide valves 35 and 2| in the lower position shown in Figure 1 there is pressure above both slide valves which, together with the weight oi' the solenoid plungers and in combination with the suction against the lower faces of the valves keeps the slide valves in this position. If, however, valve |39 is opened then suction is applied to the chamber |25 above valve 95 and this suction, together with the torce of spring |3I, is sunlcient to counteract the weight oi' the solenoid plunger |43 and lift the slide valve 95 to the position of Figure 2 in which the system is in the slow fill position. This puts the system in the slow fill position as shown in Figure 2.

If the manual valve |36 is also opened the system is moved to the fueling position shown in Figure 3. Suction is applied through pipe |35 to the upper side o! the slide valve |2| and that valve is lifted which closes the evacuation valve 39 as described in connection with Figure 3. Thus by the use of manual valves |36 and |39 the system may be operated in the event of failure of the automatic control system for any reason.

While we have shown and described certain preferred valve and control arrangements these are to be understood to be illustrative only as the system is capable of variation to meet diil'ering conditions and requirements and we contemplate such modications as come within the spirit and scope of the appended claims.

We claim:

1. In a liquid dispensing system, a pump having an inlet passage connected tc a source of liquid, a discharge passage connected to the pump, a discharge valve controlling ilow through said discharge passage, a common chamber connected to the discharge passage, an evacuation passage connecting the common chamber and the pump inlet passage, an evacuation valve controlling ilow from the common chamber to the evacuation passage, a dispensing passage leading from the common chamber, a by-pass passage connecting the discharge side of the pump and the source of liquid, a by-pass valve controlling now through the by-pass passage and an inlet valve controlling ilow from the. source of liquid to the pump inlet e, suction and pressure operating means for the discharge valve. the evacuation valve, the by-pass valve and the inlet valve, and valve controlled passages for selectively conducting pressure and suction from the pump to said valve operating means.

2. In a liquid dispensing system, a pump having an inlet passage connected to a source oi liquid, a discharge passage connected to the pump. a discharge valve controlling ilow through said discharge passage, a common chamber connected to the discarge passage, an evacuation passage connecting the common chamber and the pump inlet passage, an evacuation valve controlling iiow from the common chamber to the evacuation passage, a dispensing passage leading from the common chamber, a by-pass passage connecting the discharge side of the pump and the source of liquid, a by-pass valve controlling ilow through the by-pass passage, an inlet valve controlling ilow from the source of liquid to the pump inlet passage, suction and pressure operating means for the discharge valve, the evacuation valve, the by-pass valve and the inlet valve, valve controlled passages for selectively conducting pressure and suction from the pump to said valve operating means and solenoids for operating the valve controls for the passages leading to the valve operating means.

3. In a liquid dispensing system, a pump having an inlet passage connected to a source of liquid, a discharge passage connected to the pump. a discharge valve controlling flow through said discharge passage, a common chamber connected to the discharge passage, an evacuation passage connecting the common chamber and the pump inlet passage, an evacuation valve controlling flow from the common chamber to the evacuation passage, a dispensing passage leading from the common chamber, a by-pass passage connecting the discharge side of the pump and the source of liquid, a by-pass valve controlling flow through the by-pass passage, an inlet valve controlling ilow from the source of liquid to the pump inlet passage, suction and pressure operating means for the discharge valve, the evacuation valve, the by-pass valve and the inlet valve, valve controlled passages for selectively conducting pressure and suction from the pump to said valve operating means, solenoids for operating the valve controls for the passages leading to the valve operating means, an electronic system for controlling operation of the solenoids and control switches for the electronic system.

4. In a liquid dispensing system, a, source of liquid, a pump connected to the source of liquid, a dispensing hose connected to the pump, a bypass passage connecting the outlet and inlet sides of the pump, a valve in the by-pass passage whereby the pressure of fluid supplied to the dispensing hose is controlled, electrically controlled means for actuating the valve in the by-pass passage, and a pressure operated switch for operating the electrically controlled means, said switch being responsive to the pressure of liquid transmitted from the pump to the hose.

5. In a liquid dispensing system, a source of liquid, a pump connected to the source of liquid, a dispensing hose and nozzle connected to the pump, a by-pass passage connecting the outlet and inlet sides of the pump whereby the pressure and quantity of the liquid delivered from the pump to the dispensing hose may be reduced.

a by-pass valve controlling the by-pass passage, an' electric control system for theby-pass valve, a pressure controlled switch adjacent the nozzle and responsive to fluid pressure in thev hose, said switch being connected inthe electric control system to close the by-pass valve when said switch is operated by uid pressure.

6. In a liquid dispensing system, a source of liquid, a pump connected to the source of liquid, a meter connected to the discharge side of the pump, a counter associated with the meter, a clutch for connecting the meter and counter, electric operating means for the clutch, a dispensing hose and nozzle connected to the discharge side of the meter, a by-pass passage connecting the discharged and inlet sides of the pump, a bypass valve for controlling flow through'the bypass passage, an electrically controlled operating means for the by-pass valve, an electric control'systemlfor the counter clutch and the electric by-pass valve operating means, a pressure switch responsive to fluid pressure in the hose, said switch being connected in the electric control system to close the clutch to connect the counter to the meter and to close the by-pass valve when pressure in the hose reaches a predetei-mined amount.

7. In a liquid dispensing system, a liquid pump, a meter connected to thedischarge side of the pump, a counter associated with the meter, a clutch for selectively connecting the meter to the counter, an electric control for actuating the clutch, said clutch being normally disconnected, a pressure operated switch adapted to be closed by a predetermined fluid pressure in the hose, said switch being connected in the clutch control circuit to operate the clutch to connect the I counter to the meter when the switchisv, closed.

8. In a liquid dispensing system, a liquid pump, a meter connected to the discharge side of the pump, a counter associated with the meter, a clutch for selectively connecting the meter to the counter, an electric control for actuating the clutch, said clutch being normally disconnected, a pressure operated switch adapted to be closed by a predetermined iluid pressure in the hose, said switch being connected in the clutch control circuit to operate the clutch to connect the counter to the meter when the sgvitch is closed and manual means for actuating the clutch independently of the electric control.

9. In combination with a liquid dispensing system including a pump, sages connecting the pump inlet and outlet and the hose, and valves controlling said passages whereby liquid may be selectively supplied to the hose at low and high pressure and withdrawn from the hose, an electronic control system for a dispensing hose, pas- 'to withdraw' liquid from actuating the valves and for actuating the clutch said valves, said system comprising solenoids for controlling the valves, relays for controlling the solenoids, an electronic tube having a plate, grid. and cathode, the relays being connected in the plate circuit, and switch controlled circuits for varying the grid bias to control relay operation. one of said circuits shifting the liquid supply to said hose from low to high pressure, the switch for said circuit being associated withthe hose and actuated by low pressure liquid in the hose, a meter connected between the pump and hose, a counter associated with the meter, a clutch for connecting the counter to the meter, a solenoid for actuating the clutch, and a relay for controlling the solenoid, the relay being connected in the circuit for shifting the liquid supply to the hose from low to high pressure whereby the clutch is actuated to connect the counter to the meter when the pressure is shifted to high.

10. In combination with a liquid dispensing system, including a pump, a meter connected to the discharge side of the pump, a counter associated with the meter, a clutch for connecting the counter to the meter, a dispensing hose connected to the outlet side of the meter, liquid passages connected to the pump outlet and inlet sides, valves controlling ilow through said passages whereby the pump will selectively deliver liquid at high or low pressure or withdraw liquid from the meter and hose, .valves being normally in position the meter. solenoids for to connect the counter to the meter, relay controlled circuits for actuating the solenoids, an electronic circuit including a tube having a plate, grid and cathode, the relays being connected in parallel in the plate circuit, and switch controlled circuits .for varying the grid bias to control relay operation, one relay operating the solenoid to cause low pressure discharge under certain bias conditions and said relay and a second relay controlling high pressure flow and counter clutch solenoids both operating under different bias conditions.